Refrigerating apparatus



May 1, 1929. CRAMER Re. 17,288

REFRIGERATING APPARATUS 4 Sheets-Sheet 1 4 Sheets-Sheet 3 May 7, 1929.

Ori inal Filed June 1921 1%, XL"; /ya

R. CRAMER HEFRIGERATING APPARATUS 4 Sheets-Sheet 4 May 7, 1929.

Original F11 a Tuna 4 1 91 type thereof in which a flooded receptacle or Reiaued May '7, 1929.

UNITED STATES PATENT OFFICE."

nom'r errant-a,v or mwaum'wrswusnr, Assrexon, at m! moms, 'ro rmemm concurrent, A OOBPOBA'IIOI or nmwm mmemrme Arman-us.

Original No. 1,642,015, emu September 1:, :13am; Io. rupee, fled June 4, an. Application to:

reissue fled February 1!. 1989. Serial No. 889,254.

' My invention relates to refrigerating aparatus in which a refrigerant such as sulfhr dioxid is employed and to the flooded evaporator is used for the liquid refrigerant. One of the objects of my inventlon 1s to provide an efiicient and reliable a paratus of this t pe having a novel means or regulating t e liquid level in the eve orator, which means is-characterized by a va ve controlling the inlet of refrigerant into the evaporator and governed by the action of a trapped body of refrigerant which is separate and independent from the'liquid refrigerant in the evaporator, with the result that the proper predetermined level of the refrigerant in the evaporator is maintained.

Another objectof my invention is to provide a novel and eificient system of refri eration includin the type of apparatus a ove described and a series of independently controlled cooling coils or refrigerators operating in conjunction with a single plant or apparatus of the type above described.

In the drawings Fig. 1 is an elevation partly in section and somewhat in diagram of a system embodying my invention and accomplishing the first above named object; Fig. 2 a longitudinal section on the line 2-2 of Fig. 3; Fig. 3 a sectional elevation on a line 33 of Fig. 2; Fig. 4 a section on the line 44 of Fig. 3; Fig. 5 an enlarged detail view showing the means for insulating the control chamber from the evaporator; Fig. 6 a longitudinal section of an evaporator and associated parts illustrating a modified form of construction; and Fig. 7 an elevation partly in section showing the apparatus accomplishing the second mentioned object of my invention.

Referring to the particular embodlment of my invention as shown in Figs. 1 to 5 the refrigerating apparatus proper includes a motor operated compressor, a condenser, an

evaporator, all of which are properly connected together by conduits or piping, and cooling means of some kind such as a cooling coil. As shown in Fig. 1 the compressor 1 which may be of any desired type is driven by a motor such as the electric motor 2. The condenser 3 may likewise be of any desired type and provided with the coil 4 through which the cooling water circulates for cooling the compressed gas pump by the compressor through the pipe 5 into the eondenser wherein the gas is condensed to the liquid form as indicated at 6 in the bottom of the condenser. A

The flooded receptacle 7 which will be hereinafter for convenience termed the evaporator, may be of any suitable shape and dimensions and the same is connected with the compressor-and with the condenser. This evaporator is connected with the suction of the compressor by the pipe 8, such connection forming the outlet connection of the evaporator, and such evaporator is connected w1 the inlet connection for such evaporator.

The evaporator is provided in its interior with a heat absorbing coil 10 which is submerged within the liquid refrigerant therein.

' This coil is connected by means of the pipes erating element.

The electric motor 2 is adapted to be controlled by meansof any suitable type of pressure controlled switch such as that indicated at 15,the same being in the present instance operated by a collapsible dia phragm 16 which is in turn operated by the pressure admitted thereto from the evaporator through the pipe 17. This switch is connected by the wires 18 with the electric motor.

The means for regulating the liquid level in the evaporator is shown in detail in Figs. 2 to 5. The evaporator is provided at one end with a removable head 19 provided with an opening 20 through which projects apart of the controlling valve mechanism which is mounted in the plate 21. This plate is secured to the head 19 in suitable manner as by means of the screws 22. To this plate and preferably heat insulated therefrom is a control chamber 23 which has marginal flanges 24 attached to the plate 21 through the interposed ring 25 of insulating material. As shown in Fig. 5 the securing means are special screws 26 which together with the the condenser by the pipe 9 which forms hole through the ring 25 is enlarged so as not to contact the shank of the screw. As

' a result the chamber 23 is insulated from the ring 21 and the evaporator.

The inlet pipe 9 is connected passage 28 in the plate 21 and communicates with a valve chamber 29 whose outlet port 30 is governed by check valve such as the spring pressed ball 31. .This outlet communicates with the passage 32 extending into the evaporator and adapted to supply the latter with the liquid refrigerant. The check valve or ball is automatically operated and is opened when the liquid in the evaporator reaches a predetermined low point and is closed when the liquid reaches its proper predetermined level.

The automatic means for controlling the valve which governs the inlet connection to the evaporator consists in the present instance of a device which broadly speaking is a pressure controlled movable member, in the present instance a collapsible diaphragm or expansible chamber 33 located within the control chamber 23 and of less sizethan the interior of such chamber so as to leave an intervening space therearound for a body 34 of liquid refrigerant which is trapped therein. The interior of the collapsible diaphragm communicates with the evaporator through a vent passage 20 and through a liquid supply passage 20. This collapsible diaphragm is provided with an annular flange 35 which is clamped between the flange 24 and the ring 25. The collapsible diaphragm is provided with a stem 36 guided in the outward extension 37 of the plate 21 and extendin into the enlarged passage 30 and adapted to contact the ball 31 and force the same from its seat when moved inwardly.

Next describing the cooling coil and its associated parts, the same is preferably provided with a circulating pump 38 for maintaining circulation through the coil although the same could be maintained by thermal action. As shown this pump which may be of an suitable character, is driven by the electric motor 39 which may be controlled by any suitable switch but in the present instance I have shown a cont-r01 consisting of a bulb 40 arranged within the cooling chamberand adjacent the coolin coil and containing a volatile liquid, te pressure of which is conducted to the collapsible diaphragm 41 through the pipe 42. This collapsible diaphragm operates the switch 43 which is connected by the electric wires 44:"

with the motor 39.

Describing the operation of this flooded with a radial -freezingliquid, such as brine or diluted alcohol circulates. A. part of the pipe system contalning this circulating liquid is the cooling coil 13 which is here shown located in the refrigerator. The circulation through this pipe system is enforced in the present instance by means of the circulating pump 38. In the present instance this circulating pump 38 is driven by it own electric motor.

39 and such motor is stopped and started by the switch 43 which is under the influence of the thermostat or bulb 40. Under the action of thisthermostat, the motor 39 is started when the temperature in the refrigerator reaches a predetermined high point and such motor is stopped again when the temperature in the refrigerator reaches a predetermined low point. As the pressure of'the volatile liquid in this bulb 4O chan es with changes of temperature, the collapsi le diaphragm 41 expands or contracts, thereby operating the switch 43. I

When a certain pre-determined high-pressure in the evaporator is reached the motor 2 which operates the compressor is automatically started and when a pre-determined low pressure in the evaporator is reached such motor is automatically stopped. The switch 15 which accomplishes this purpose is shown as of the collapsible diaphragm operated type and any suitable type of pressure controlled switch may be used for this purpose. y The above mentioned pressure variations in the evaporator correspond to temperature changes of the liquid refrigerant in the evaporator. When the refrigerant in the evaporator absorbs heat from the coil 10, its temperature and consequently its pressure rises. When the pressure of the refrigerant in the evaporator is reduced, due to the action of the compressor, itstemperature also pressor may be automatically stopped and started under the influence of a thermostat immersed in the liquid in the evaporator, with the same results as the above described pressure regulation.

Describing the action of the automatic means or collapsible diaphragm 33 which regulates the liquid level in the evaporator, the collapsible diaphragm is partially filled V evaporator.

in its interior with the same liquid refrigerant as in the evaporator and to the same level thereof and it is surrounded at its outer end and sides with the trapped body 34"of the same character of liquid refrigerant, the chamber 23 being insulated from the evaporator so as not to be affected by the temperature thereof which would otherwise be conducted through the end head and plate 21. \Vhen the liquid level in the evaporator falls below the pro-determined level and when for instance this level is below the line of the passage 20". there will be no liquid inside of the collapsible diaphragm, the small residue therein evaporating rapidly. The trapped liquid between the collapsible diaphragm and influence of the outside temperature will be warmer; than the. liquid within the evaporator. The pressure of this trapped refrigerant will therefore be higher than the pres- .sure inside the evaporator with the result that this higher pressure will compress the collapsible diaphragm and force the stem 36 inwardly forcing the ball valve from its seat against the tension of thespring and interposed disk 46 and admitting a supply of liquid refrigerant through the passages 30 and 32. When the liquid level'in the evaporator rises, cold liqui diaphragm 33 and by heat conduction through the walls of the collapsible d1aphragm the temperature of the trapped liquid is reduced with the result that the pressure of such trapped liquid will be likewise reduced. As a result the spring 45 will seat the valve and close the inlet against further admission of the li uid refrigerant'to the It will e understood that any suitable liquid may be employed in the space around the collapsible diaphragm 33 but I prefer to employ the same liquid as used in the evaporator.

The above described control means have the effect of operating the electric'motor 2 in accordance with the requirements of the rcfrigerator. When the conditions in the refrigerator are such that a small amount of refrigeration is required, then the circulating pump 38 will remain idle for long periods of timewhich in turn will cause the refrigerant in the evaporator to remain at low temperature and consequently at low' pressure for long periods of time. This in turn causes the motor 2 to remain idle for corresponding long periods of time. If on the other hand the refrigerator requires a large amount of refrigeration, the motor 39 will operate the circulating pump 38 at frequent intervals which will in turn influence the temperature and consequently the pressure of the refrigerant in the evaporator, with the result that there will be frequent or long period operations of the motor 2.

In Fig. 6 I have shown a modified form' the chamber or cap 23 being under the enters the collapsiblein the basement.

posed movable dish '54. This ball controls a port leading from the chamber 51 tothe inlet or supply passages 55 in the chamber 56 of the casing. This chamber is in constant communication with the interior of the evaporator and has the same liquid level as the latter.

The casing 48 is provided with a removable cap 57 which is secured thereto by the screws 58, between which casing and cap there is clamped the margin of a movable abutment "or diaphragm 59. To this diaphragm there is secured a stem 60 whose lower end is adapted to contact and force the ball valve 52 from its seat when this diaphragm is operated. The space or chamber 61 above the diaphragm communicates by means of pipe 62 with a control chamber 63 which in the present instance surrounds a by-pass pipe connection 64 communicating with the evaporator atdiiferent heights thereof. This chamber 63 contains a volatile liquid preferably the same kind of liquid refrigerant as employed in the evaporator.

When the evaporator level lowers the liquid within the chamber 63 will become heated by outside temperature and the pressure .thereof will increase which pressure will be transmitted through the pi ie 62 to the diaphragm whereupon an a ditional supply of the refrigerant will be admitted -to the evaporator. \Vhen the proper liquid level in the evaporator is reached the liquid in the chamber 63 will be cooled by such admitted liquid and the pressure upon the -top of the diaphragm 59 will be relieved,

great practical utility wherever a number of refrigerators are used in substantially close proximity as for instance in apartment buildings and the like. In Fig. 7 I have shown such a system, illustrating the same in a building of three stories with the refrigerating apparatus onthe first floor or As shown the evaporator 65 is connected to the compressor 66 by the .pipe 67 and with the condenser-68 by the pipe 69.?The water circulation pipes for the condenser are shown at 70. Theevaporator is connected to the pressure controlled switch .71 which governs the motor 72, through the pipe 73. The evaporator is also provided with the main" supply and return pipes 74 and 75'which extend upwardly through the floors 76, 77 and 78 ofv the building 79 and connect byv means of takeoff pipes with a series of refrigerating coils 80, 81 and 82 located in the refrigeratorsv 83, 8d: and 85 respectively. These take-off pipes indicated at 86 and 87 are similar for each refrigerator and the remainder of the apparatus and connections associated with each refrigerator are the same, including thecirculating pump 88, motor 89 and switch 90 connected with the bulb 91 through the pipe 92. It will be understoodthat the pipes 74 and 75 contain brine or diluted alcohol in the same manner as the corre-' sponding pipes 11 and 12 shown in Fig. l. The operation and control are the. same as described above in connection-with the apparatus of Fig. 1 but it will be understood that the refrigerators are separately and independently controlled according to the temperature in any particular refrigerator.

As an additional feature each circulating pump motor may be provided with an individual'electric meter such as shown at 93. As the refrigerating liquid such as brine or diluted alcohol will be circulated in aecor dance with the requirements of'eachindividual refrigerator, the amount of the current consumed by thecirculatin'g pump motor is proportionate'to the amount of refrigeration used in each individual refrigerator. The charge for the service can then be properly based on the circulating pump motor meter reading.

' this pump is intermittent, responding to high andl'ow refrigerator temperatures, the

nections for the refrigerant, and therm'o-' static means responding to a fall in level of said liquid refrigerant and cooperating with one of said connections for maintaining the level of the refrigerant inthe evaporator within predetermined limits.

2. Refrigerating apparatus of the class described, comprising an evaporator normally containing therein a quantity of liquid refrigerant and having inlet and outlet connections for the refrigerant, and thermo- In case the operation of static means cooperating with one of said connections formaintaining the level of the r frigerant in the evaporator within predetermined limits, said thermostatic means be ing disposed in direct-but varyingheat-exchange relationship with the body of liquid refrigerant in said evaporator.

l 4. Refrigerating apparatus of the class described,- comprising an evaporator containing therein a body of liquid refrigerant and having'inlet and outlet connectionsfor the refrigerant, and mechanism for regulating the level of the refrigerant in the evaporater, comprising a valve governing such inlet connection, an expansible thermostatic member spaced from the main body of'liquid refrigerantin said evaporator and adapted to control such valve, and conduit means for establishing, a liquid-refrigerant connection between-the main body of refrigerant and said expansible thermostatic member.

5. Refrigerating apparatus of the'class described, comprising an evaporator contain ing therein a body of.liquid refrigerant and having mlet'a'nd outlet connections for the refrigerant, and mechanism for regulating the level of the refrigerant in the evaporator, comprising a valve governing such inlet c0nneat-ion, an expansible thermostatic member spaced from the main body of liquid refrigerant in said evaporator and adapted to control such valve, and conduit means for establishing a liquid-refrigerant connection between the main body of refrigerant and said expansible thermostatic member, said conduitmeans including aliquid passage below the normal high level of the liquid refrigerant and a vent passage above the normal high level of the liquid refrigerant.

6. Refrigerating apparatus of the class described, comprising an evaporator containing therein a body of liquid refrigerant and having inlet and outlet connections for the refrigerant, and mechanism for regulating the level of the refrigerant in the evaporator comprising an expansible chamber disposed in heat-exchange relationship with said body of refrigerant and containing an expansible fluid therein, and a 'valve governing such inlet connection and itself controlled by said expansiblc chamber.

7. Refrigerating apparatus of the class described, comprising an evaporator 0on maps ing therein a body of liquid refrigerant and having inlet and outlet connections for therefrigerant, and mechanism for regulating the level of the refrigerant in the evaporator comprising an ex ansible chamber containing an ex ansibe fluid therein, said expansible c, amber having a metallic -cor rugated bellows movable wall adjacent the evaporator and disposed in reentrant relationship with the remainder of the expansible chamber, and a valve governin such inlet connection and itself controlled by the movable wall.

9. Refrigerating apparatus of the class described, comprising an evaporator containing therein a body of liquid refrigerant and having inlet and outlet connections for the refrigerant, and mechanism for regulating the level of the refrigerant in the evaporator comprising an expansible chamber. containing an'expansible fluid therein, said expansible chamber having a cup-shaped member, a metallic corrugated bellows within the cupshaped member, one end of the bellows being sealed by an end wall and the other end being sealed with the cup-shaped member, means for establishing a heat-exchange rela tionship between the corrugated bellows and said body of refrigerant, a valvegoverning the inlet connection, and a connection between said end wall and said valve for actuating the latter.

,10. Refrigerating apparatus of the class described, comprising an evaporator normally containing therein a quantity of liq uid refrigerant and having inlet and outlet connections for the refrigerant thermostatic means cooperating with one of said connections for maintaining the level of the refrigerant in the evaporator within predetermined limits, said evaporator having aside opening, and a plate removably secured in said opening and supporting said thermostatic means.

11. A refrigerating system including a series of cooling chambers, cooling means therein, main supply and return pipes for the refrigerant common to all such. cooling means, individual pairs of supply and return pipes connecting between each cooling means immersed in the said body of liquid refri y 115 and such main pipes, indeplendently controlled pum s associated wit said individ: ual pairs 0 pipes, and a refrigerating apparatus including an evaporator connected with said main pipes and a condenser and a' compressor connected with each other andwith the evaporator.

12. Refrigerating apparatusof the class described, comprising a chamber normally containing, therein a ligand-cooling agent, and thermostatic means r maintaining the level of said liquid-cooling agent within predetermined limits, said means comprisin an expansible chamber thermally isolate from said cooling agent and in heat-exchange relationshi with the. atmosphere, and means establis ing a heat-exchange relationship between said cooling agent and said expansible chamber.

13. In apparatus for cooling liquids, the

combination of a closed refrigeration Sys- 1 tem including means for lique ying refrigerant vapor and a vaporizer chamber adapted to receive the liquefied refrigerant; a conduit for the liquid to be cooled comprising a heat absorbing section having its wall in contact on one side with the liquid refrigerant in the vaporizer; means associated with the conduit by which the liquid to be cooled is subject to demand intermittently at variable rates; and means operating automatically with change of temperature of the liquid refrigerant 1n the vaporizer chamber to vary the operation. of the refrigerant liquefying means and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said section of the conduit being proportioned to direct the liquid to be cooled in a predetermined path.-

14. In apparatus for cooling liquids, the

combination of a closed refrigeration system including a means for liquefying refrigerant vapor, a vaporizer chamber, and means operating in conjunction with the refri erant liquefying means for automatica' y maintaining a body of li uid refrigerant in said chamber; a conduit or the'liquid to be cooled comprising a heat absorbing section erant; means associated with theconduit which the liquid to be cooled is subject to demand intermittently at variable rates; and means operating automatically with change of temperature of the liquid refrigerant 1n the vaporizer chamber to stop and start the refrigerant liquefying means and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said immersed section of the conduit being proportioned to direct the liquid to be cooled in a predetermined path.

15. In apparatus for cooling liquids, the combination of a closed refrigeration system including a motor driven compressor,.a condenser, a vaporizer chamber, and means operating in con'unction with the compressor and con enser for automatically maintaining a body of li uid refrigerant in said chamber; a conduit or the liquid to be cooled comprising a heat absorbing section immersed in the said body of liquid refrigerant; means associated with the conduit by which the liquid to be cooled is subject to demand intermittently at variable rates; and means operating automatically with change of temperature of the liquid refrigerant 1n the vaporizer chamber to stop and start the compressor and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said immersed section of the conduit being proportioned to direct the liquid to be cooled in' a predetermined path.

16. In apparatus for cooling flowing liquids, the combination of a closed refrigeration system including means for liquefying refrigerant vapor and a vaporizer chamber adapted to receive the liquefied refrigerant; a conduit for the liquid to be cooled com prising a heat absorbing section having its wall in contact on one side with the liquid refrigerant in the vaporizer; means associated with the conduit causing variation of the heat content of the liquid entering said heat absorbing section of the conduit per unit of time; and means operating automatically with change of temperature of the liquid refrigerant in the vaporizer chamber to vary the operation of the refrigerant liquefying means and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said section of the conduit being proportioned to direct the liq-v uid to be cooled in a predetermined path.

17. In apparatus for cooling flowing liquids, the combination of a closed refrigeration system including a means for liquefying refrigerant vapor, a vaporizer chamber, and

means operating in conjunction with the refrigerant liquefying means for automatically maintaining a body of liquid refrigerant in said chamber; a conduit for the liquid to be cooled comprising a heat absorbing section immersed in the said body of liquid re frigerant; means associated with the conduit causing variation of the heat content of the liquid entering said heat absorbing section of the conduit per unit of time; and means operating automatically with change of temperature of the liquid refrigerant. 1n the vaporizer chamber to stop and start the refrigerant liquefying means and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said immersed section of the conduit being proportioned to direct the liquid to be cooled in a predetermined path.

18. In apparatus for cooling flowing liquids, the combination of a closed refrlgeration system including a motor driven compressor, a condenser, a vaporizer chamber, and means operating in conjunction with the compressor and condenser for automatically maintaining a body of liquid refrigerant in said chamber; a conduit for the liquid'to be cooled comprising a heat absorbing section immersed in the said body of liquid refrigerant; means "associated with the conduit causing variation of the liquid entering the said heat absorbing section of the conduit per unit of time; and means operating automatically with change of temperature of the liquid refrigerant in the vaporizer chamber to stop and start the compressor and thereby maintain the temperature of the said liquid refrigerant within a limited predetermined range; the said immersed section of the conduit being proportioned to direct the liquid to be cooled in a predetermined path.

In testimony whereof I hereby ailix my signature.

ROBERT GRAMER. 

